The present invention generally relates to plug-in counter systems of the type disclosed in British Pat. No. 855,114, published Nov. 30, 1960 and entitled "Improvements In Or Relating To Counting Devices" and having a plug-in counter module adapted to be axially inserted into a plug-in counter receptacle operating system for remote electrical operation of the plug-in counter module and more particularly relates to a new and improved plug-in counter module useful with most conventional plug-in counter receptacle operating systems.
Several companies are engaged in the manufacture and sale of plug-in counter systems having a plug-in counter receptacle with female electrical terminals and a plug-in counter module with corresponding male electrical terminals and adapted to be inserted into the receptacle for electrically connecting the plug-in counter module for remote electrical operation by a predetermined electrical pulse or signal. Although the physical size of the plug-in counter modules and plug-in counter receptacles has been generally standardized by the principal companies engaged in their manufacture, the position of the female terminals is not standardized and so that each plug-in counter module is useful with only some of the available receptacle operating systems. Therefore, commercially available plug-in counter modules are not completely interchangeable and any replacement plug-in counter module must have a specified design which is compatible with the plug-in counter receptacle operating system with which it is to be used.